1. Field of the Invention
This invention is concerned with a process of making naphthyl acetals. More particularly it is concerned with a method for making such acetals which involves the step of reacting a naphthol with an alkyl vinyl ether in the presence of an aliphatic acid catalyst.
2. Discussion of the Prior Art
The general process of making naphthyl acetals from naphthols and vinyl ethers is well known in the art. As described in U.S. Pat. No. 3,497,181, such method involves the reaction of naphthol and a vinyl ether. Specifically, it is disclosed therein that 1-naphthol may be reacted with n-butyl vinyl ether to yield n-butyl naphthyl acetal [designated as 1-n-butoxy-1(1-naphthoxy) ethane in Example 2 of the patent]. The patent discloses also that an acid catalyst such as p-toluene sulfonic acid can be used as catalyst in the reaction involving a vinyl ether and a hydroxyaromatic compound. But as will appear hereinafter, this acid, when used in the usual catalytic amount, is not a catalyst for the reaction of this invention.